Electrons in hydrogen like atom `(Z= 3)` make transtion from the fifth is the fourth orbit and from the third orbit The resulting madition are incided nurmally an a meal plate and eject photoelectron the stopping potential for the photoelectron ejected by the longer wavelength
(Rydhery constant` = 1.094 xx10^(7) m^(-1)`

Answer

B, D

Explanation

for hydrogen like atom energy of the nth orbit is
`E_(n) = (13.6)/(n^(2))Z^(2) eV atoms`
for transition from `n = 5 to n = 4`
`h nu = 13.6 xx 9 [(1)/(16) - (1)/(25)] = (13.6 xx 9 xx 9)/(16 xx 25) = 2.754 eV`
for transition from `n = 4 to n = 3 `,
`hv' = 13.6 xx 9 [(1)/(9)- (1)/(16)] = (13.6 xx 9 xx 7)/(9 xx 16) = 5.95 eV` for transition `n = 4 to n = 3 ,` the frequency is high and lence wavelength is short
for photoelectrnic effect , `hv' - W = eV_(0)` where `W= work`
function
`5.95 xx 1.6 xx 10^(-19) = 2 eV`
Again appling `hv - W= eV_(0)`
we get `2.754 xx 1.6 xx 10^(-19) - 2 xx 1.6 xx 10^(-19) = 1.6 xx 10^(-19)= V_(0)`
`rArr V_(0) = 0.754eV`